Comparison of blind, ultrasound- and neurostimulator-guided methods of percutaneous inferior alveolar nerve block

Background: An inferior alveolar nerve block is often utilised for anaesthesia of the mandibular arcade of teeth prior to dental procedures. It has been described with multiple approaches and methods; however, at the current time, no direct comparison of percutaneous methods is available. Objectives: To compare the accuracy of percutaneous infiltration of the inferior alveolar nerve with a ventral blind approach (control) to blind caudal approach, ultrasound-guided and neurostimulator-guided methods. Study design: Prospective comparison of methods using anaesthetised horses prior to euthanasia or cadavers, being utilised for another study. Methods: An 18 G spinal needle was used to inject a volume of 1 ml, composed of 0.5 ml of methylene blue and 0.5 ml of iodinated CT contrast medium, with placement guided by the aforementioned methods. Following injection the needle was left in place, CT-imaging was performed and then the skulls were dissected. CT enabled assessment of the coverage of the mandibular foramen with contrast medium and distance of the needle tip from the mandibular foramen and dissection enabled assessment of the staining of the inferior alveolar nerve and lingual nerve. Results: The highest percentage of contrast staining of the inferior alveolar nerve and coverage of the mandibular foramen at CT was achieved with caudal blind and ultrasound-guided approaches; however, no group reached a significant difference to control (ventral blind approach). Concurrent staining of the lingual nerve (possibly associated with undesired side effects) had high incidence and was similar between groups. Main limitations: Use of horses under anaesthesia/cadavers does not replicate clinical conditions and staining/coverage is assumed to relate to a clinically effective block. Conclusions: Ultrasound-guided and caudal approaches did have increased percentage of successful staining, but neither reached significance compared to the ventral blind approach

Anesthesia, Sedation, and Pain Management of Donkeys and Mules

The number of donkeys in the world may not be increasing but awareness of their use and concern for welfare and pain recognition and treatment are receiving increasing veterinary interest. Therefore, accurate information about anesthesia and analgesia in donkeys and mules is important to more equine practitioners. This review highlights the current knowledge on various anesthetic and analgesic approaches in donkey and mules. The authors emphasize that there is still much information that is not available about donkeys and mules; in many circumstances, the clinician must use available equine information to treat the patient, while monitoring for differences in response

Monitoring equine head-related pain with the Equine Utrecht University scale for facial assessment of pain (EQUUS-FAP)

This study validates a recently described pain scale, the Equine Utrecht University scale for facial assessment of pain (EQUUS-FAP), in horses with acute or postoperative pain originating from the head, including dental pain, ocular pain, or trauma to the skull. This cohort study of 23 horses with head-related pain and 23 normal, healthy controls revealed significant differences in EQUUS-FAP scores between control horses and horses with acute or postoperative pain (P

Anesthesia, Sedation, and Pain Management of Donkeys and Mules

The number of donkeys in the world may not be increasing but awareness of their use and concern for welfare and pain recognition and treatment are receiving increasing veterinary interest. Therefore, accurate information about anesthesia and analgesia in donkeys and mules is important to more equine practitioners. This review highlights the current knowledge on various anesthetic and analgesic approaches in donkey and mules. The authors emphasize that there is still much information that is not available about donkeys and mules; in many circumstances, the clinician must use available equine information to treat the patient, while monitoring for differences in response

Fixation of Hydrogel Constructs for Cartilage Repair in the Equine Model : A Challenging Issue

Objective: To report on the experiences with the use of commercial and autologous fibrin glue (AFG) and of an alternative method based on a 3D-printed polycaprolactone (PCL) anchor for the fixation of hydrogel-based scaffolds in an equine model for cartilage repair. Methods: In a first study, three different hydrogel-based materials were orthotopically implanted in nine horses for 1-4 weeks in 6 mm diameter full-thickness cartilage defects in the medial femoral trochlear ridge and fixated with commercially available fibrin glue (CFG). One defect was filled with CFG only as a control. In a second study, CFG and AFG were compared in an ectopic equine model. The third study compared the efficacy of AFG and a 3D-printed PCL-based osteal anchor for fixation of PCL-reinforced hydrogels in three horses for 2 weeks, with a 4-week follow-up to evaluate integration of bone with the PCL anchor. Short-term scaffold integration and cell infiltration were evaluated by microcomputed tomography and histology as outcome parameters. Results: The first study showed signs of subchondral bone resorption in all defects, including the controls filled with CFG only, with significant infiltration of neutrophils. Ectopically, CFG induced clear inflammation with strong neutrophil accumulation; AFG was less reactive, showing fibroblast infiltration only. In the third study the fixation potential for PCL-reinforced hydrogels of AFG was inferior to the PCL anchor. PCL reinforcement had disappeared from two defects and showed signs of dislodging in the remaining four. All six constructs fixated with the PCL anchor were still in place after 2 weeks. At 4 weeks, the PCL anchor showed good integration and signs of new bone formation. Conclusions: The use of AFG should be preferred to xenogeneic products in the horse, but AFG is subject to individual variations and laborious to make. The PCL anchor provides the best fixation; however, this technique involves the whole osteochondral unit, which entails a different conceptual approach to cartilage repair